I have a Rheem Criterion II RGPH-07EAUER. When I it is in the first part of its cycle, before it ignites, the fan is loud and makes a hissing sound. It goes away when the main circulating fan comes on.

t1m130

• 86 Answers
• Posted on Jul 26, 2009

SOURCE: Are there any recalls on a Rheem Criterion II

there have been several situations wht rheems as far as control boards cracked heat exchangers cracked inducer assemblys and touchy pressure switches i would call to get a furnace inspection from a rheem dealer

sounds like you really need to buy a portable dehumidifier

SOURCE: I HAVE A RHEEM CRITERION 2 gas furnace, when i

Usually a bad flame sensor will cause this problem.
You can either replace it or clean it with some extra fine steel wool.

SOURCE: Have a rheem criterion II. Model

The way it lights is that the gas is spread from one burner to the next by either a flame tray or small holes drilled in the burner tubes. If the flame does not get all the way across the burner tubes within a few seconds, the unit goes out on failure. Clean and inspect each burner tube, not just the orifice. Clean any tray that connects the burners. You can use a small wire brush or tooth brush but be careful near the glow igniter as it is very fragile.

SOURCE: My Rheem Criterion II gas furnance is not igniting

On a call for heat, the 24 volt thermostat sends a signal to the control module. The control module will indicate a call for heat with a light on the control either blinking or remain solid depending upon model. The inducer (exhaust) blower will purge all gasses from the furnace and pressurize a pressure switch. Once the pressure switch tells the module to continue, the electronic ignition will energize and send 120 volts to the igniter. The igniter will glow and you will be able to see it if viewed thru the small inspection port. Once the igniter gets hot enough, it sends a signal to the module opening up the gas valve (24 volts). Either a pilot will come on or the burner tube will ignite then spread the flame to all burners. Lastly a safety sensor will be looking for a certain temperature within a few seconds and the furnace will continue to operate and the room air blower will turn on in a minute or two.

What could go wrong? The unit will not run if there is no signal from the thermostat (bad thermostat or broken wire), the control module does not sense a signal from the thermostat (bad control), the inducer does not energize (bad motor), the pressure switch does not close (blocked vent piping, bad switch, plugged condensate hose), the igniter does not energize (bad control, bad igniter), the gas valve does not open or there is no gas (bad gas valve, broken wire, no gas), the pilot does not light (dirty pilot), the burner does not light (bad burner, plugged orifice, not enough combustion air), the flame does not spread to each burner (bad flame spreader, dirty flame spreader, more bad burners), the flame safety sensor does not detect flame (dirty or bad flame spreader, bad flame sensor, broken wire, bad control), or the room air blower does not energize (bad fan motor, bad control).

SOURCE: I have a Rheem Criterion II Gas Furnace that has

Turn off the power to furnace.
on the last burner to light there is a small metal rod in front of the burner. This is a safety called the flame sensor. It is dirty. Unscrew it from the bar ( 1 Screw) unplug the connector wire from it and clean it with steel wool. it will be kind of burnt. Plut back in place and turn on the furnace to cycle.